High-Resolution Modeling of Methane Plumes: Validation and Sensitivity Experiments to Explore Emission Quantification...

Area of Science:

• Environmental science
• Atmospheric science
• Computational fluid dynamics

Background:

• Quantifying methane (CH4) emissions from various sources is challenging due to complex plume dynamics and atmospheric variability.
• Satellite and aerial platforms detect CH4 plumes, but accurate quantification is hindered by fine-scale atmospheric changes.
• Uncrewed aerial vehicle (UAV) measurements face uncertainties in plume quantification.

Purpose of the Study:

• To address uncertainties in UAV-based CH4 plume measurements.
• To validate the fire dynamics simulation (FDS) model in large eddy simulation (LES) mode for CH4 plume quantification.
• To enhance the accuracy of methane emission quantification methods.

Main Methods:

• Employed fire dynamics simulation (FDS) in large eddy simulation (LES) mode.
• Utilized mean wind data derived from LiDAR datasets.
• Validated the FDS model with in situ CH4 concentration data from UAVs during controlled release experiments.

Main Results:

• FDS accurately reproduced the magnitude and spatiotemporal variations of observed CH4 plumes for pipes with diameter >0.6 cm.
• Gas exit velocity, obstacles, and terrain topography significantly impact near-field plume dynamics.
• Gas temperature influences plume behavior at higher mass flow rates.

Conclusions:

• High-resolution LES modeling, specifically FDS, adds significant value to understanding CH4 plume dynamics.
• The validated FDS-LES model can improve current methane emission quantification methods.
• Accurate CH4 emission quantification is crucial for environmental monitoring and mitigation efforts.